Patent GB-190610020-A (GB)
Title: Improvements in and relating to Fluid Pressure Brake Systems.
Filed: 1906-04-30
Granted: 1907-04-25
Abstract: 10,020. British Themsen-Houston Co., [General Electric Co.]. April 30. Brakes.-In a combined pneumatic and electric control air-brake system, the pneumatic and electric operating-means are controlled by the same handle, and, except in emergency applications, the pneumatic means are automatically cut out of action so long as the electric means are in operation ; the electricallyoperated distribution valve on each vehicle is adapted to give a graduated application and release, and to be de-energized in the running position, thereby economizing current. The driver's valve D, Fig. 1, is adapted to connect the train-pipe C to the main reservoir B or, in pneumatic applications, to atmosphere. The usual pneumaticallyoperated triple valve E and an electrically-operated valve H are each adapted to connect the brake cylinder G to the auxiliary reservoir F or to atmosphere, a double-throw check valve I being employed to cut out one or other of the valves E, H. The valve H comprises a slide valve, Fig. 2, which is connected to the cores j, k of magnets J, K. This slide valve works in a chamber which is in communication with the auxiliary reservoir, and controls ports g, a leading to the brake cylinder and atmosphere respectively. The valve is shown in the running position, in which both magnets are de-energized and the brake cylinder is open to the atmosphere, the contact m<1> on the driver's-valve handle being in the position shown. When the driver's valve is turned to application position, the contact m<1> engages the contact m<3>, when, if the electric controlling-means are in order, the atmospheric port of the driver's valve is automatically closed, as explained below, and the magnet J is energized. This moves the valve H to the left to open the brake-cylinder port g to the auxiliary reservoir. If the contact m<1> is now moved back into the space between the contacts m<3>, m', so that the magnet J is de-energized, the valve H is returned, by a spring L, to a lap position somewhat to the left of the position shown in Fig. 2. By successively energizing and de-energizing the magnet J, the application of the brakes can be graduated. When the contact m' is moved on to the contact m<2>, the magnet K is energized; this moves the valve H to another lap position to the right of the position shown. When the driver's valve is returned to its running position shown, the magnet K is de-energized, and a spring L' returns the valve H to its release position, Fig. 2. By successively energizing and de - energizing the magnet K, a graduated release can be effected. The driver's valve shown in Fig. 4 carries the electric contacts m on the stem of its rotary valve D, which is shown on its seat in Fig. 5. In the release position, shown in both Figures, a passage d through the valve puts the main - reservoir pipe b in communication with a port c<1> leading to the trainpipe c. A hook-shaped cavity d' in the valve D has its inner end always over a port a<1>, which is connected to the atmosphere through a valve o. In the service-application position, the cavity d' connects the train-pipe port c<1> to the port a<1>, but, if the electric control is in order, a magnet M, which is in series with the contact m<3>, Fig. 1, is then energized, whereby the valve o is moved to close the port a<1> to the atmosphere, so that the electric operating means only are actuated. If, however, the electric system is not in use, the valve o will remain open, so that the train-pipe will be vented and the triple valves E operated in the usual way. In an emergency application, a cavity d' connects the train-pipe port c' to a port a<2> which is in direct communication with the atmosphere, and the triple valves are moved to their emergency positions whether the electric system is in operation or not.